persp fail with non-equidistant dates
On 22/08/2016 11:17 AM, Tomas Bayer wrote:
Hello, when I plotted non-equidistant data in 3D (using persp and contour), it was ended with the same error message:
persp(y, x, z, xlab="latitude", ylab="longitude", zlab="altiude",
main="Altitude") Error in persp.default(y, x, z, xlab = "latitude", ylab = "longitude", : increasing 'x' and 'y' values expected How to fix it? The original data are in columns 50.84925 14.65715 614.0 48909.14 -62.49 99 48929 5 122306 50.84919 14.65702 617.0 48816.32 -145.82 69 48836 6 122331 50.84908 14.65681 622.0 49113.40 6.64 99 49133 4 122442
You haven't shown us what is in y, x and z, but it looks as though you haven't got data in the form required by persp, i.e. a vector of increasing values in each of the first two arguments, and a matrix of values in the third. Using your variable names, you'd want z[i,j] to correspond to y[i] and x[j]. If you just have a collection of (y, x, z) triples, you'll need to do some pre-processing to fit a surface and produce the required inputs. Duncan Murdoch